Tramming a mill head is the process of adjusting a milling machine's mill head and spindle to be precisely perpendicular to a tool holding work surface or mill table. Typically, the tool holding spindle is vertical and the mill head is horizontal in a vertical milling machine. The tool holding spindle extends out of the mill head to adjust cutter depth and controls movement of the tool relative to the mill head surface. The mill table holds or disposes a work product to be shaped, drilled and otherwise formed by the tool. Perpendicularity assures that the action of the tool on the work product is predictable but other angles between the tool spindle and the mill head may be used when desired.
Tramming a mill head to the mill table is not only necessary in the initial setup of a milling machine but also necessary in the periodic maintenance over the life of the machine. Conventional tramming techniques involve rotating a test gauge held in an arm adapter in the spindle for measuring the precise distance between the test gauge and multiple points on the mill table. The angle of the mill head's upright support is adjusted until there are no differences in the test gauge readings. This requires iteratively adjusting the mill head for each point by half the difference between any two points until all points on the mill table read the same distance from the test gauge. This lengthy process not only requires skill, proper tools, techniques and methods but also a lot of time.
Tramming is usually preformed by the machinist prior to and during large amounts of work or prior to especially precise work. Time taken in tramming a milling machine comes out of the productive time a machinist has to produce a work product. Therefore, the longer it takes to tram a machine, the less time a machinist has to produce work product. A system and method which speeds up the tramming process with the same or better accuracy compared to conventional techniques will enable the machinist to be more productive and profitable and even produce superior products.